衬塑泵结构流固耦合分析及参数优化

发布时间：2018-04-11 22:31

本文选题：衬塑泵 + 流固耦合　；参考：《安徽工程大学》2017年硕士论文

【摘要】：泵是使用十分广泛的机械,在农业和工业等领域都有着十分重要的地位。近年来,随着有色冶炼等的发展,对于离心泵的耐腐蚀性要求越来越高。与金属泵相比,衬塑泵以其优秀的耐腐蚀特性得到了广泛的应用,对于衬塑泵的研究也愈来愈重要。泵的结构参数是决定其效率高低的关键因素,在保证离心泵工作效率的同时还要保证其稳定性。汽蚀破坏一直是破坏离心泵稳定性的一个主要原因。除此之外,由于叶轮受力变形将会造成叶轮前间隙的改变:当间隙过小时,非常容易造成叶轮的磨损,对泵造成破环,使泵的寿命受到影响;当间隙过大时,将会出现泄漏多,效率低的问题。鉴于此,本文以提高衬塑泵的效率、减小汽蚀破坏为目标对衬塑泵进行了研究。根据衬塑泵性能要求,运用速度系数法,对衬塑泵进行了水力设计,得到各过流部件结构参数,建立了衬塑泵的三维模型;对衬塑泵进行内部流场模拟,得到了衬塑泵在设计工况下的速度、压力及气体含量情况,并进行了分析,发现了汽蚀发生的位置,对衬塑泵的效率进行了初步估算;综合考虑影响泵性能的主要结构参数,选取叶轮进口直径Dj、出口宽度b2,叶片出口角β2以及叶片数Z作为正交试验的的四个因素设计并完成了正交试验,对试验结果进行了极差分析,得到了各因素相对效率和汽蚀性能指标的权重程度及影响顺序;建立以效率损失和汽蚀余量最小的目标函数,基于遗传算法对衬塑泵结构参数进行多目标寻优,得到了衬塑泵最优结构参数组合,并通过CFD软件模拟验证了其合理性;基于ANSYS Workbench平台,采用流固耦合的方法对衬塑泵进行结构分析,得到了叶轮在流固耦合作用下的受力形变情况,根据在叶轮上建立的挠度曲线得到了叶轮各点的受力位移变化情况。本文通过对衬塑泵内部流场的数值模拟,以提高衬塑泵效率、降低汽蚀余量为目标,选取了叶轮的主要性能影响参数,设计完成了正交试验并对试验结果进行了极差分析;运用遗传算法对参数进行了优化,得到了衬塑泵的最优结构参数组合,提高了衬塑泵的整体性能;通过ANSYS Workbench软件对衬塑泵进行了流固耦合分析,得到了衬塑泵在流固耦合作用下叶轮的受力变化情况,对衬塑泵在实际工况下遇到的因叶轮受力变形造成的叶轮前盖板的磨损问题以及涡室进口宽度的设计具有指导意义。
[Abstract]:Pumps are widely used machinery, in agriculture and industry and other fields have a very important position.In recent years, with the development of non-ferrous smelting, the corrosion resistance of centrifugal pumps is becoming more and more high.Compared with metal pump, liner pump has been widely used for its excellent corrosion resistance, and the research on liner pump is becoming more and more important.The structural parameters of the pump are the key factors to determine its efficiency.Cavitation failure is always a main reason for destroying the stability of centrifugal pump.In addition, the deformation of the impeller will cause the change of the front clearance of the impeller: when the clearance is too small, it is very easy to cause the impeller to wear and tear the pump, which will affect the pump's life; when the clearance is too large, there will be more leakage.The problem of inefficiency.In view of this, the aim of this paper is to improve the efficiency of liner pump and reduce cavitation damage.According to the performance requirements of the liner pump, the hydraulic design of the liner plastic pump is carried out by using the velocity coefficient method, and the structure parameters of each flow part are obtained, the three-dimensional model of the liner plastic pump is established, and the internal flow field of the liner plastic pump is simulated.The velocity, pressure and gas content of the liner pump under the design condition are obtained, and the cavitation position is found out, the efficiency of the liner plastic pump is preliminarily estimated, and the main structural parameters affecting the pump performance are considered synthetically.Four factors, including impeller inlet diameter Dj2, outlet width b _ 2, blade outlet angle 尾 _ 2 and blade number Z, were selected as four factors to design and complete orthogonal test.The relative efficiency of each factor and the weight degree and influence order of cavitation performance index are obtained, the objective function of minimum efficiency loss and cavitation margin is established, and the multi-objective optimization of the structural parameters of the plastic lining pump is carried out based on genetic algorithm.The optimal structure parameter combination of liner pump is obtained, and its rationality is verified by CFD software simulation. Based on ANSYS Workbench platform, the structure of liner pump is analyzed by fluid-solid coupling method.The deformation of impeller under fluid-solid coupling is obtained, and the displacement of impeller at each point is obtained according to the deflection curve established on the impeller.In this paper, through the numerical simulation of the internal flow field of the liner plastic pump, in order to improve the efficiency of the liner pump and reduce the cavitation allowance, the main parameters affecting the performance of the impeller are selected, the orthogonal test is designed and the range analysis of the test results is carried out.Genetic algorithm is used to optimize the parameters, the optimal structural parameters of the liner pump are obtained, the overall performance of the liner pump is improved, and the fluid-solid coupling analysis of the lined plastic pump is carried out by ANSYS Workbench software.The stress variation of the impeller under the fluid-solid coupling is obtained, which is of guiding significance to the wear problem of the front cover of the impeller and the design of the inlet width of the vortex chamber, which is caused by the deformation of the impeller under the actual working conditions.
【学位授予单位】：安徽工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH311

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